Missed call notification to cellular telephone using short text messaging

ABSTRACT

A system for and method of providing Short Message Service (SMS) message notification to a cellular telephone customer regarding missed incoming calls that are missed while the cellular telephone is powered off. This is accomplished by generating a notification message at a SS7 gateway that includes caller ID/name ID information and/or time of the missed call. The message is preferably generated at the SS7 gateway only upon receipt of an “access denied” response with a reason code of “inactive” that is sent from a home location register in response to a location request sent by the SS7 gateway. Once the generated message is complete it is request sent to a message center where it is stored until it is retrieved by the cellular telephone soon after registration with the cellular network.

BACKGROUND

1. Field of the Invention

The present invention is directed to cellular telephone system callfeatures and management. More particularly, the present invention isdirected to a system for and method of notifying a cellular telephonecustomer of a missed call using a short text message.

2. Background of the Invention

Cellular telephone usage has been growing at an exceptional pace. Peopleuse cellular telephones for a variety of reasons including safety,increased availability while away from a conventional wireline/landlinetelephone and/or because cellular telephone services provided bycellular telephone providers can offer greater value compared toconventional wireline service. In all cases, however, cellular telephonecustomers typically seek a reliable alternative to conventional wirelinemeans of communication wither because they are away from the wirelinemeans of communication, or because access to those means ofcommunication is inconvenient.

To enhance a cellular telephone customer's sense of staying in touch,cellular telephone service providers offer voice mail service as one ofmany service offerings. This well-known service causes an incoming callto a cellular telephone, which is not available to receive the incomingcall, to be forwarded to a voice mail service where the caller can leavea message for the cellular telephone customer. Typically, an incomingcall will be forwarded to voice mail when the cellular telephone ispowered off (i.e., not registered), when the cellular telephone is beingused (and no call waiting feature is available), or when the cellulartelephone customer configures his cellular telephone to forward incomingcalls to voice mail even though the cellular telephone is powered on andavailable to receive calls.

Since voice mail is often an add-on feature that is not typicallyincluded in basic service plans offered by cellular telephone serviceproviders, customers who desire voice mail must pay extra for thisservice. However, not all customers are willing to pay the full fee forvoice mail service. On the other hand, some of these same customersmight still desire a service that provides information regardingincoming calls that might have been missed.

SUMMARY OF THE INVENTION

The present invention addresses and overcomes the drawbacks of having tooffer only conventional cellular telephone voice mail service tocellular telephone customers by providing Short Message Service (SMS)message notification to a cellular telephone customer about incomingcalls that are missed while the customer's cellular telephone is poweredoff. That is, the present invention provides a means for notifying acellular telephone customer of missed calls (at least those that aremissed because the cellular telephone is not registered) withoutrequiring the cellular telephone customer to purchase a relativelyexpensive voice mail add-on feature or option as part of their cellulartelephone service plan. The present invention is operable with bothlandline and cellular telephone-originated calls.

In the landline-originated implementation the present invention ispreferably implemented in a telecommunications infrastructure includinga landline telephone that is connected to a central office (CO), whichitself is connected to an SS7 gateway. The SS7 gateway is able tocommunicate with both a SMS message center and a home location register(HLR), which is often incorporated with a mobile switching center (MSC).The MSC, in turn, is in communication with cellular telephones. Inaccordance with the present invention, in addition to employing the SS7gateway to perform well-known call setup functions, the SS7 gateway isprogrammed or is modified to include a “message generator,” whichbecomes operable when the HLR returns, in response to a location requestquery from the SS7 gateway, an “access denied” response with the reasonbeing that the called cellular telephone is “not active.”

The message generator preferably generates a message containing thelandline caller ID/calling name ID and any other text message that willfit within the remaining portion of the maximum allowable characters ina SMS message. The information for creating the SMS message is availableat the SS7 gateway since the CO typically provides that information tothe gateway when the landline call is originally placed. The generatedSMS message preferably also includes the time that the missed call wasattempted.

Once the message is complete it is sent to the message center where itis stored in memory until the called cellular telephone is powered onand registers. At that time the MC delivers the short message that wasgenerated, originally, at the SS7 gateway, thereby providing missed callnotification to the cellular telephone customer.

Thus, the present invention provides numerous advantages, not the leastof which is that a cellular telephone customer can receive a missed callnotification service that, while not as extensive as voice mail service,nevertheless provides useful and timely information to the customerabout missed calls. Further, the cost to implement the service of thepresent invention is relatively low since it is not necessary topurchase and field expensive voice mail systems to retain messages.Accordingly, customers will be more willing to purchase the lessexpensive service.

When the call originates from another cellular telephone, the call ispassed to a servicing mobile switching center (MSC) and associated SS7gateway in which the message generator of the present invention may beimplemented.

It is therefore an object of the present invention to provide methodsand systems for providing missed call notification to cellulartelephones from landline or cellular telephones.

It is another object of the present invention to provide a missed callnotification using a short message service message.

It is another object of the present invention to provide notification ofa missed call due to a cellular telephone that is powered off.

It is also an object of the present invention to provide a messagegenerator that is co-located or integral with a SS7 gateway.

It is another object of the present invention to generate short messageservice messages at a SS7 gateway and pass those messages to a messagecenter where the messages await distribution to wireless devicecustomers, including cellular telephone customers.

It is yet another object of the present invention to block or filterpredetermined missed call notifications using a message generator at aSS7 gateway.

These and other objects of the present invention will become apparentupon a reading of the following detailed description in conjunction withthe accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an exemplary telecommunicationsarchitecture in which the present invention can be implemented.

FIG. 2 is an exemplary chart illustrating events that typically occurbetween and among the components shown in FIG. 1 when a landlinetelephone attempts to call a mobile telephone, in accordance with thepresent invention.

FIG. 3 is a schematic diagram of another exemplary telecommunicationsarchitecture in which the present invention may be implemented.

FIG. 4 is an exemplary chart illustrating events or steps that typicallyoccur between and/or among the components shown in FIG. 3 when a mobiletelephone attempts to call another mobile telephone, in accordance withthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides notification to a cellular telephonecustomer (or other wireless device customer) about missed incoming callsresulting from the customer's cellular telephone being powered off. Thatis, the present invention provides a means for notifying a cellulartelephone customer of missed calls (at least those that are missedbecause the cellular telephone is not registered) without requiring thecellular telephone customer to purchase a relatively expensive voicemail add-on feature or option for their cellular telephone service plan.

FIG. 1 is a schematic diagram of an exemplary telecommunicationsarchitecture in which the present invention can be implemented. Landlinetelephone 100 is connected to central office (CO) 110. CO 110 isconnected to an SS7 gateway 120, which is used in its conventional wayto set up calls between central office 100 and other nodes, such asanother central office (not shown) or a mobile switching center 130. Ofcourse, CO 100 and SS7 gateway 120 can be co-located as shown by dottedenclosure 125. Also shown in connection with SS7 gateway is MessageGenerator 127, which will be explained in more detail below. SS7 gateway120 is preferably in communication with mobile switching center (MSC)130, which typically includes or has access to a home location register(HLR) 140. SS7 gateway 120 is also preferably in communication with ashort message service (SMS) message center (MC) 150.

SMS is a means by which short messages can be sent over the air from abase station, such as MC 150, to wireless digital devices includingdigitally-enabled cellular telephones. Alphanumeric messages up to 160characters can be supported according to well-known protocols. As withthe CO and SS7 gateway, MSC 130, HLR 140 and MC 150 can also beco-located as shown by dotted enclosure 155.

Finally, as is conventional, MSC 130 is connected to or is incommunication with a base station or antenna 160, which communicateswith cellular telephone 170, sometimes referred to herein as a mobiletelephone.

In accordance with the present invention, a cellular telephone customercan receive a notification of a missed call while his cellular telephonewas powered off. This is achieved by generating and sending a SMS textmessage comprising the name and number of the caller who was trying toreach the cellular telephone. A more detailed explanation of the variousaspects and embodiments of the present invention is set forth below.

FIG. 2 is an exemplary chart illustrating events or steps that typicallyoccur between and/or among the components shown in FIG. 1 in accordancewith the present invention. In the following example, a telephone callis placed from a landline telephone to a mobile telephone. Referring toFIG. 2, a call originates from the landline telephone 100 and connectsto CO 110 (event 200). CO 100 recognizes the dialed digits sent fromtelephone 100 as they are entered on the keypad and then sends thecellular telephone number (i.e., the dialed digits) and thelandline/calling line ID or calling name ID to SS7 Gateway 120 (event202). As mentioned previously, SS7 is a signaling system that is usedfor setting up calls between offices, nodes, and other components of thetelephone network. Because the dialed number is recognized at the SS7gateway as a cellular telephone number, SS7 gateway 120 sends a locaterequest (LOCREQ) to home location register (HLR) 140 using well-knownoperating software within the gateway (event 204).

As is well known in the art, the home location register (HLR) is adatabase that contains cellular telephone customer or subscriberprofiles. If the cellular telephone to which the call is directed is notpowered on at the time the HLR receives the location request, then theHLR returns an “access denied” message with a reason code of “mobileinactive” (event 206). If the cellular telephone customer does not havevoice mail, then SS7 gateway 120 forwards the inactive notification tocentral office 110 and then ultimately back to the landline caller. Amessage is typically played for the landline caller that indicates thatthe mobile or cellular telephone is not available. In prior art systems,the sequence of events typically ends here, assuming the cellulartelephone customer does not subscribe to voice mail.

In accordance with the present invention, however, when an access deniedmessage with a reason code of “mobile inactive” is received at SS7gateway 120, SS7 gateway 120 not only causes a message to be played forthe landline caller indicating the called cellular telephone is notavailable, but the SS7 gateway also creates, via Message Generator 127,a SMS message containing the landline caller ID/calling name ID (event208) and any other text message that will fit within the remainingportion of maximum allowable characters in the SMS. Message Generator127 preferably comprises one or more software routines and or hardwarecomponents that can be programmed to provide the functionality describedherein. The information for creating the SMS message is available at theSS7 gateway since CO 110 provided that information to the gateway whenthe landline call was originally placed. That is, SS7 gateway 120 and/orMessage Generator 127 preferably buffers the calling number, and alsothe mobile telephone number that was called so that this informationremains available for creating the SMS message in the event such amessage is desired. The SMS message preferably includes the telephonenumber (and preferably also name) of the calling party. The time of thecall may also be included.

Once the message is complete it is sent to MC 150 via the well-knownIS41 standard SMS Deliver request (event 210). Message centers capableof receiving SMS messages are well-known in the art. MC 150 accepts themessage (event 212) and sends a SMS request (event 214) to HLR 140.Because the cellular telephone to which the SMS message is directed isnot powered on, HLR 140 returns a SMS Request N-ack response (event 216)and simultaneously sets a flag within HLR 140 that a message is waitingin MC 150 (not shown).

Later, when cellular telephone 170 is powered on, it registers with thecellular system (event 218), namely, HLR 140. HLR 140, having previouslyset a message waiting flag for the cellular telephone customer, sends aSMS notify message to MC 150 (event 220). MC 150 then sends another SMSRequest (event 222), which is answered by HLR 140 with a SMS Request Ack(event 224). Thus, the short message that was generated, originally, atthe SS7 gateway is passed to and acknowledged by cellular telephone 170via the well-known Short Message Data Point to Point (SMDPP) and SMDPPAcknowledge exchange (events 226 and 228).

Advantages of the foregoing system are evident. For example, it isrelatively simple to generate the short message at the SS7 gateway sinceall the information is being buffered there in any event. Moreover, thetriggering event for generating the short message, namely, a “LOCREQ,access denied” communication, is received by the SS7 gateway and thus isreadily available to Message Generator 127. Further still, a cellulartelephone customer can receive a level of service that, while not asextensive as voice mail, nevertheless provides useful and timelyinformation to the customer about missed calls. Further still, the costto implement the service of the present invention is relatively lowsince it is not necessary to purchase and field expensive voice mailsystems to retain messages.

FIG. 3 is another exemplary telecommunications architecture in which thepresent invention may be implemented. FIG. 3 shows the case where acellular telephone 300, rather than a landline telephone, is attemptingto contact another cellular telephone 170. Thus, FIG. 3 shows a cellulartelephone 300, a base station or antenna 310, a MSC 320, a SS7 gateway330, with the latter two components capable of being co-located as shownby dotted enclosure 335. SS7 gateway 330 preferably also includesMessage Generator 337, which is functionally similar to MessageGenerator 127.

FIG. 4 is a chart illustrating the events or steps that occur betweenand/or among the components shown in FIG. 3 when a mobile telephoneattempts to call another mobile telephone that is powered off. As shown,a call originates from cellular telephone 300 and is passed to MSC 320(event 400). In this case, both of the mobile telephone numbers ormobile identification numbers (MINs) are passed to MSC 320. MSC 320 thenpasses that information to SS7 Gateway 330 (event 402). The dialednumber is recognized at the SS7 gateway as a cellular telephone numberand, as such, SS7 gateway 330 sends a locate request (LOCREQ) to homelocation register (HLR) 140 using well-known operating software withinthe gateway (event 404).

If the called cellular telephone, i.e., cellular telephone 170, is notpowered on at the time the HLR receives the location request, then theHLR returns an “access denied” message with a reason code of “mobileinactive” (event 406), which triggers a message to be played on cellulartelephone 300 indicating that the called mobile or cellular telephone isnot available. In prior art systems, the sequence of events typicallyends here, assuming the cellular telephone customer does not subscribeto voice mail.

In accordance with the present invention, however, when an access deniedmessage with a reason code of “mobile inactive” is received at SS7gateway 330, SS7 gateway 330 not only causes a message to be played forthe calling cellular telephone indicating the called cellular telephoneis not available, but the SS7 gateway also creates a SMS messagecontaining the calling cellular telephone's MIN and/or name ID (event408) and any other text message that will fit within the remainingportion of maximum allowable characters in the SMS. The information forcreating the SMS message is available at the SS7 gateway since MSC 320provided that information to the gateway when the cellular telephone 300call was originally placed. That is, SS7 gateway 330 preferably buffersthe calling number and called MINs (MIN1 and MIN2), so that thisinformation remains available for creating the SMS message in the eventit is desired. The time of the call may also be included as can be asmall message such as, “a call from xxxxx was missed at date, hh:mm”.

Once the message is complete it is sent to MC 150 via the well-knownIS41 standard SMS Deliver request (event 410). MC 150 accepts themessage (event 412) and sends a SMS request (event 414) to HLR 140.Because the cellular telephone to which the SMS message is directed isnot powered on, HLR 140 returns a SMS Request N-ack response (event 416)and simultaneously sets a flag within HLR 140 that a message is waitingin MC 150.

When cellular telephone 170 is powered on, it registers with thecellular system (event 418), namely, HLR 140. HLR 140, having previouslyset a message waiting flag for the cellular telephone customer, sends aSMS notify message to MC 150 (event 420). MC 150 then sends another SMSRequest (event 422), which is answered by HLR 140 with a SMS Request Ack(event 424). Thus, the short message that was generated, originally, atMessage Generator 337 is passed to and acknowledged by cellulartelephone 170 via the SMDPP and SMDPP Acknowledge exchanges (events 426and 428).

Thus, whenever an SS7 gateway is involved in setting up a call to acellular telephone that is SMS-enabled and that cellular telephone ispowered off at the time of the attempted call setup, a MessageGenerator, which can be integral with the SS7 gateway, preferablygenerates a short message in accordance with the SMS standard (or anyother similar standard or protocol that is receivable by the cellulartelephone or other mobile device) and that message is sent to a messagecenter. The message is then automatically retrieved and displayed by thecalled cellular telephone when that cellular telephone is powered on andregisters.

The present invention should not necessarily be construed to be limitedto automatically generating messages for all missed calls. Rather, thedescribed notification feature or service is preferably enabled only forthose customers who request the feature as part of their cellulartelephone service plan.

Also, Message Generator 127 or 337 is also preferably programmable tofilter calls. For example, a cellular telephone customer who primarilyuses his telephone for business and regularly calls his office while onthe road does not need to know that his office called while his mobiletelephone was powered off since he will likely be calling his officeanyway. On the other hand, that customer would want to know about othercalls that may have been missed. Accordingly, Message Generator 127 or337 preferably includes a calling party filtering table or list that isused to disable the notification feature for predetermined telephonenumbers.

The present invention also provides a competitive advantage to cellulartelephone service providers that also operate conventional landlinetelephone systems. Specifically, landline telephone service providerswill typically control and manage central offices and associated SS7gateways throughout the telephone network, whereas cellular telephoneservice providers do not control or manage central offices. Thus, onlylandline telephone service providers are able to control whether a SS7gateway can be configured in accordance with the principles of thepresent invention. That is, unless central offices and associated SS7gateways include the functionality described herein, a cellulartelephone customer cannot receive a missed call notification from alandline-placed call. In view of the foregoing, service providers thatoffer both cellular and conventional landline services can offercellular telephone customers enhanced service (namely, missed callnotification for landline as well as mobile originated calls) thatcellular service-only providers cannot offer.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be obvious to oneof ordinary skill in the art in light of the above disclosure. The scopeof the invention is to be defined only by the claims appended hereto,and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

1. A method of providing missed call notification to a cellulartelephone, comprising the steps of: receiving a telephone call, which isdirected to a cellular telephone, at a central office; generating amessage at an SS7 gateway including information identifying the originof the telephone call; sending the message to a short message service(SMS) message center; and forwarding the message to the cellulartelephone when the cellular telephone registers with the home locationregister, thereby providing notification of a missed call.
 2. The methodof claim 1, further comprising generating the message only when thecellular telephone is not registered with the home location register. 3.The method of claim 1, further comprising generating the message onlywhen the cellular telephone is powered off.
 4. The method of claim 1,wherein the message comprises at least one of a telephone number fromwhich the telephone call originated, a name and a time of the telephonecall.
 5. The method of claim 1, further comprising filtering telephonecalls for which notification is provided.
 6. The method of claim 1,wherein the home location register is associated with a mobile switchingcenter.
 7. The method of claim 1, wherein an incremental cost to acustomer for receiving missed call notification in accordance with claim1 is less than an incremental cost to the customer for voice mailservice.
 8. A method of providing missed call notification, comprisingthe steps of: receiving a telephone call from a first cellulartelephone, which is directed to a second cellular telephone, at a mobileswitching center; generating a message at an SS7 gateway that is incommunication with the mobile switching center, the message includinginformation identifying the origin of the telephone call; sending themessage to a message center; and forwarding the message to the secondcellular telephone when the second cellular telephone registers with thehome location register, thereby providing notification of a missed call.9. The method of claim 8, further comprising generating the message onlywhen the second cellular telephone is not registered with the homelocation register.
 10. The method of claim 8, further comprisinggenerating the message only when the second cellular telephone ispowered off.
 11. The method of claim 8, wherein the message comprises atleast one of a telephone number from which the telephone calloriginated, a name and a time of the telephone call.
 12. The method ofclaim 8, further comprising filtering telephone calls for whichnotification is provided.
 13. The method of claim 8, wherein the homelocation register is associated with a mobile switching center.
 14. Themethod of claim 8, wherein an incremental cost to a customer forreceiving missed call notification in accordance with claim 8 is lessthan an incremental cost to the customer for voice mail service.
 15. Themethod of claim 8, wherein the message is a short message service (SMS)message.
 16. A system for providing missed call notification to acellular telephone, comprising: a central office operable to receive atelephone call, which is directed to a cellular telephone; an SS7gateway in communication with a central office operable to receive callsetup information that is representative of the telephone call and senda location request communication to a home location register based onthe call set up information; a message generator operable to generate,in response to the home location register, a message at the SS7 gatewayincluding information identifying the origin of the telephone call;means for sending the message to a message center; and means forforwarding the message to the cellular telephone when the cellulartelephone registers with the home location register, thereby providingnotification of a missed call.
 17. The system of claim 16, wherein themessage is generated only when the cellular telephone is not registeredwith the home location register.
 18. The system of claim 16, wherein themessage is generated only when the cellular telephone is powered off.19. The system of claim 16, wherein the message comprises at least oneof a telephone number from which the telephone call originated, a nameand a time of the telephone call.
 20. The system of claim 16, furthercomprising means for filtering telephone calls for which notification isprovided.
 21. The system of claim 16, wherein the home location registeris associated with a mobile switching center.
 22. The system of claim16, wherein the same business entity operates both the central officeand a cellular telephone network.
 23. The system of claim 16, wherein anincremental cost to a customer for receiving missed call notificationvia the system of claim 16 is less than an incremental cost to thecustomer for voice mail service.
 24. The system of claim 16, wherein themessage generator is implemented in one of hardware, software or acombination thereof.
 25. The system of claim 16, wherein the message isa short message service (SMS) message.
 26. A system for providing missedcall notification, comprising: a mobile switching center operable toreceive a telephone call from a first cellular telephone, which isdirected to a second cellular telephone; means for forwarding call setupinformation that is representative of the first cellular telephone callfrom the mobile switching center to an SS7 gateway and sending alocation request communication to a home location register; a messagegenerator operable to generate a message at the SS7 gateway includinginformation identifying the origin of the telephone call; means forsending the message to a message center; and means for forwarding themessage to the second cellular telephone when the second cellulartelephone registers with the home location register, thereby providingnotification of a missed call.
 27. The system of claim 26, wherein themessage is generated only when the cellular telephone is not registeredwith the home location register.
 28. The system of claim 26, wherein themessage is generated only when the cellular telephone is powered off.29. The system of claim 26, wherein the message comprises at least oneof a telephone number from which the telephone call originated, a nameand a time of the telephone call.
 30. The system of claim 26, furthercomprising means for filtering telephone calls for which notification isprovided.
 31. The system of claim 26, wherein the home location registeris associated with a mobile switching center.
 32. The system of claim26, wherein the same business entity operates both the central officeand a cellular telephone network.
 33. The system of claim 26, wherein anincremental cost to a customer for receiving missed call notificationvia the system of claim 26 is less than an incremental cost to thecustomer for voice mail service.
 34. The system of claim 26, wherein themessage generator is implemented in one of hardware, software or acombination thereof.
 35. The system of claim 26, wherein the message isa short message service (SMS) message.